4. Today’s hunter-gatherers are ever vigilant against free-riding and elite-exploitation—both as threatening to team survival as any predator. They rigidly enforce social rules by ridicule, shaming, shunning, exile and even execution. This ensures skilled cooperators fare better than self-maximizers (e.g. another stakeholder always distributes meat, never whoever made the kill).

5. Enforced rules create strong selection pressures. The cheapest strategy to avoid social penalties is preemptive self-control. Such impulse control has always been adaptive.

12. By improving social productivity, rules beat no rules. Our social-rule processors work just like our language-rule processors (both evolved for social coordination). We automatically absorb the (often tacit) rules of our culture’s grammar and behavioral norms (we detect grammar errors unconsciously just like we often detect behavioral rule violations).

14. Once social-rule processors arose, their cultural configurations also became subject to evolution’s “productivity selection.” We’re descended from those with the fitter traits, and tools, and rules (=higher productivity moralities).